1. Field of the Invention
The present invention relates to an image pick-up device and an endoscope, and more particularly to an image pick-up device and endoscope which are easily assembled.
2. Description of the Related Art
Conventionally in the medical field, medical endoscopes in which an insertion portion of an elongated endoscope is inserted by an operator or the like into a body cavity have been widely used to observe organs and the like inside the body and perform various curative procedures when necessary using procedural instruments inserted into an instrument channel. In the industrial field, industrial endoscopes in which the elongated insertion portion is inserted into the interior of boilers, turbines, engines, chemical plants, and soon have been widely used to observe and inspect interior damage, corrosion, and so on.
In particular, endoscopes used in the medical field in which an insertion portion is inserted into a body cavity are used to observe organs and the like and to perform various treatments or procedures using procedural instruments inserted into an instrument channel of the endoscope. Hence, when an endoscope or procedural instrument which has been used once is reused on another patient, infection from patient to patient must be prevented. For this purpose, endoscope devices must be cleaned and disinfected following an examination or medical procedure.
Disinfection and sterilization processing of endoscopes and attachments thereof such as procedural instruments is conventionally performed using a gas such as ethylene oxide gas or an antiseptic fluid. As is well known, however, sterilization gases are highly toxic, and hence complicated procedures must be carried out during the sterilization of endoscopes and their attachments in order to ensure safety. Another problem is that a large amount of time is required to perform aeration for removing gas that has bonded to an instrument following sterilization of an endoscope and its attachments. As a result, doctors, nurses, and so on are unable to use endoscopes and their attachments immediately after sterilization. Furthermore, running costs are high.
If an antiseptic fluid is used, on the other hand, a problem arises in that management of the antiseptic drug solution is complicated. Moreover, waste processing of the antiseptic fluid involves a great deal of expense.
Hence in recent years, high pressure steam sterilization known as autoclave sterilization has gradually become mainstream. Autoclave sterilization does not involve complicated operations for disinfecting and sterilizing instruments such as endoscopes (to be referred to below as “endoscopic instruments”) that are subjected to sterilization, enables the immediate reuse of the endoscopic instruments following sterilization, and has low running costs. Autoclave sterilization is also known as general sterilization, and involves placing the endoscopic instrument under vacuum conditions prior to sterilization processing, using high-temperature water vapor to perform sterilization of even the minute portions of the instrument in a short amount of time, and then placing the endoscopic instrument in vacuum conditions again following sterilization processing in order to dry the instrument. According to U.S. standard ANSI/AAMIST37-1992, autoclave sterilization is defined such that during sterilization processing, an instrument is exposed for four minutes to approximately two atmospheres of pressure at 132° C.
As the diameter of the insertion portion of the endoscope decreases, the load on the patient lightens. Accordingly, the observable range within the body cavity of the patient increases, and reliable diagnoses can be made. Further, in endoscopes provided with a bending portion on the insertion portion that can be remote-controlled, the load on the patient lightens as the length of the rigid portion on the tip end side of the bending portion decreases. Accordingly, the observable range within the body cavity of the patient increases, and reliable diagnoses can be made.
A solid-state image pick-up device capable of capturing high-quality images is provided on the rigid tip end portion at the tip end of the insertion portion of the endoscope. This solid-state image pick-up device captures an image inside the body cavity and supplies a generated image signal to a monitor. The captured image is reproduced and displayed on the monitor on the basis of this image signal. Usage of this type of electronic endoscope provided with a solid-state image pick-up device has become commonplace.
The insertion portion of such an electronic endoscope, provided with a solid-state image pick-up device, has a small diameter, and various techniques are employed to reduce the length of the rigid portion at the tip end of the insertion portion.
For example, the endoscope image pick-up unit disclosed in Japanese Unexamined Patent Application Publication H11-47084 is constituted of a cover lens provided on the opening end of the rigid tip end portion, a lens frame for holding an observation optical system comprising a plurality of lenses disposed rearward of the cover lens, a device attachment frame to which the lens frame is fixed by attachment, and to which an infrared cut-off filter and a cover glass, which are disposed rearward of the observation optical system of the lens frame on the optical axis, are fixed by adhesion, a solid-state image pick-up device disposed at the rear end of the device attachment frame on the optical axis, a circuit board mounted with a drive-control circuit connected to an external lead of the solid-state image pick-up device and so on, and a signal line connection substrate for connecting the circuit board and the external lead of the solid-state image pick-up device to a signal cable.
To facilitate connection of the external lead of the solid-state image pick-up device and the circuit board in particular, and also to increase reliability, this image pick-up unit comprises a circuit board having a side through hole soldering land for soldering a center portion of the external lead of the solid-state image pick-up device, and a signal line connection substrate having a side through hole soldering land for soldering the rear end portion of the external lead. The signal line connection substrate is further provided with a through hole land for connecting the core wire and shield wire of the signal cable.
In the endoscope disclosed in Japanese Unexamined Patent Application Publication 2002-301025, the length of the rigid tip end portion of the endoscope is reduced by hermetically sealing a lens unit, a solid-state image pick-up device, a hybrid integrated circuit element (to be abbreviated to “HIC” below) for drive-controlling the solid-state image pick-up device, and so on provided on the tip end side of the insertion portion. Further, the members provided in the interior of the rigid tip end portion are constituted so as not to deteriorate as a result of autoclave sterilization.
In the endoscope disclosed in Japanese Unexamined Patent Application Publication 2000-60793, a frame in which a solid-state image pick-up device is accommodated and hermetically sealed is provided on the tip end portion. By providing a conductor on the outer surface of the frame and electrically connecting the conductor and solid-state image pick-up device while ensuring airtightness, the members provided inside the frame do not deteriorate as a result of autoclave sterilization.